Safer materials for the construction of jump fences in equestrian events are being considered by the sport's governing body following the latest in a series of tragedies which has resulted in the deaths of five riders in as many months.

A special safety committee has been set up by the British Horse Trials Association (BHTA) to investigate ways of making fences safer after the latest victim, Peter McLean, aged 20, fell and died during horse trials in Suffolk.

The new safety methods being considered include the use of plastic tubing instead of logs for jumps or for wooden logs that are used to be partly cut so that they break apart on impact, causing fewer injuries to horse and rider.

Other methods being investigated include the use of softer wood or plastic poles in the construction of fences. The safety committee will enlist the help of experts from other sports, such as mountaineering and cycling to discuss ways of limiting the number of accidents.

Mr McLean, who was originally from Lanark but lived in Lutton near Peterborough, was killed after his mount Gracious Me II fell at the fifth fence on the intermediate course at the Somerleyton horse trials.

His death follows a disastrous summer for the equestrian world with a record number of fatal accidents. Before the recent series of accidents, only about one rider a year died during horse trials.

Winnie Murphy, BHTA spokeswoman, said: "We are doing everything possible to prevent accidents and are trying to gather as much information as possible to make our sport safer.

"The number of deaths that have happened recently is most unusual.

"We don't know what we are doing wrong and there's nothing common in these accidents. We wish we had an explanation. Eventing is a risk sport and everybody who competes is aware of this and our committee is working as hard as it can to make it even safer."

Earlier this month, Simon Long, aged 38, died after falling from his horse at a jump during the Burghley horse trials near Stamford, Lincolnshire.

In August, Polly Phillips, a contender for the Olympic Games, was killed at the Scottish Open championships while Australian rider Robert Slade died in June when his horse rolled on him during the Wilton trials near Sailsbury, Wiltshire.

The fifth rider to have died this year was Peta Beckett, who was thrown during a cross country competition in Wiltshire.

Ms Murphy added that while the number of deaths during equestrian events this year was unusually high, last year around 160 competitions were held without any fatalities.

The British Horse Society, which looks after the interests of riders, insisted that equestrian events are still safe.

Nicola Gregory, BHS spokeswoman, said: "We still enjoy one of the best safety records in the world.

"Safety procedures are consistently under review. Riding is not a dangerous sport, and one is far more likely to get injured playing squash or football."

On average one person a year died in horse trials, whereas about 10 riders died on the roads, she said.